Bug#1025213: DRM platform with kms_swrast

[Simon McVittie]

On Fri, 16 Dec 2022 at 22:40:28 +0100, Gert van de Kraats wrote:
> If the i915 dri driver is present gnome-shell is using the DRM platform
> (not the Wayland platform?) with this driver.

This is expected. gnome-shell acts as the Wayland compositor (the X11
equivalent would be Xorg, window manager and compositing manager all
in one process), so it can't use Wayland itself, for the same reasons
that Xorg can't output via X11. It has to use something lower-level
to talk directly to the kernel, and the DRM platform is exactly that
lower-level thing.

Ordinary applications running under GNOME (when it's in Wayland mode)
will use the Wayland platform as you'd expect, it's only gnome-shell
itself that can't.

Similarly, if there is no suitable hardware-specific DRI driver available
for your hardware, it's normal and expected that gnome-shell will use
the DRM platform with some sort of software-rendering driver.

    smcv